Utility Rate Regulation - Regulatory Assets (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Regulatory Assets [Line Items]
Current regulatory assets	[1]	$ 30	$ 48
Noncurrent regulatory assets		1,765	1,733
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		4	24
Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		12	7
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		8	10
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		791	809
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		333	326
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		71	93
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		62	68
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	141
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	137
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		208	143
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	7
Noncurrent regulatory assets		14	16
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	[1]	12	13
Noncurrent regulatory assets		991	1,006
PPL Electric Utilities Corp [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		8	10
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		456	469
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		333	326
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		19	30
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		39	42
PPL Electric Utilities Corp [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	137
PPL Electric Utilities Corp [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		0	0
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		4	3
Noncurrent regulatory assets		1	2
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets		18	35
Noncurrent regulatory assets		774	727
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		4	24
LG And E And KU Energy LLC [Member] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		12	7
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		335	340
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		52	63
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		23	26
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		143	141
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		208	143
LG And E And KU Energy LLC [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		4	6
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		2	4
Noncurrent regulatory assets		9	8
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		6	16
Noncurrent regulatory assets		437	424
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		4	13
Louisville Gas And Electric Co [Member] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	0
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		211	215
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		29	35
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		16	17
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		102	98
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		77	57
Louisville Gas And Electric Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		0	0
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		2	3
Noncurrent regulatory assets		2	2
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		12	19
Noncurrent regulatory assets		337	303
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	11
Kentucky Utilities Co [Member] | Generation Formula Rate [Member]
Regulatory Assets [Line Items]
Current regulatory assets		12	7
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		124	125
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		23	28
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		7	9
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		41	43
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		131	86
Kentucky Utilities Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		4	6
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0	1
Noncurrent regulatory assets		$ 7	$ 6

[1] These amounts are included in "Other current assets" on the Balance Sheets.